Grade 8 Technology (TECH) Summaries – Term 2 (Spot On)

This document provides an overview and summaries for Grade 8 Technology, Term 2, Module 4: Impact of technology.

Module 4 Overview

The module covers the following topics:

• Positive impact of technology.
• Negative impact of technology.
• Revising the forces that act on materials.
• Reducing the negative impact of technology.

Positive Impact of Technology (Unit 1 & 2)

• Technology has greatly improved materials and enhanced natural materials, such as rope.
  • Ancient Egyptians made rope from water reeds about 6,000 years ago.
  • By the late 1700s, machines were invented to make stronger rope.
  • Modern machines produce ropes and metal cables that can handle great force.
• Natural materials are biodegradable and environmentally friendly. Plastic, developed through technology, was not originally biodegradable and caused litter and environmental problems.
• Recycling technology has improved as the demand for recycling has grown. Paper and cardboard are common recycled materials.
• Development of packaging uses cardboard and its uses include:
  • Protecting the product and keeping it clean.
  • Making it easier to pack, store, and move.
  • Containing smaller or non-solid items.
  • Informing the consumer.

Negative Impact of Technology (Unit 3 & 5)

• The negative impact can influence both the natural world and human behaviour.
• Examples of negative impacts include:
  • Factory and farming machinery can increase unemployment.
  • Electronic communication can reduce face-to-face interaction.
  • Computer games can prevent children from playing outside and getting exercise.
  • Packaging can cause pollution and litter.
• Solutions can either compensate (make up for something) or counteract (prevent or reduce) the negative impact.

Forces on a Material (Unit 4)

The main types of forces acting on materials are:

• Compression: Push the edges of the material together, squashing it.
• Tension: Pull the ends of the material apart, stretching it.
• Bending: A combination of tension and compression forces.
• Torsion: Twists the material, turning the ends in opposite directions.
• Shear: Forces try to make one part move in one direction and another part in the opposite direction (to slide past one another).

Adapting Materials

Materials are often adapted to handle forces through reinforcement, which makes the material stronger.

• Concrete is reinforced with metal beams or fibres to resist tension forces and increase strength.
• Plywood, made from wood veneer sheets, is reinforced with cotton fibre cloth to help it withstand forces.
• Metal beams and bars strengthen structures, often shaped non-solidly to save material while retaining strength.